1. Field of the Invention
The present invention relates to a radiant type thermometer for measuring the temperature of a subject based on infrared rays irradiated from the subject.
2. Description of the Related Art
There have been conventionally proposed radiant type thermometers for measuring infrared rays irradiated from the eardrum with an infrared ray sensor in a non-contacting manner to find the temperature of the eardrum (see International Publication No. 97/01083, U.S. Pat. Nos. 5,653,238, 5,628,323, 5,445,158, 5,381,796, 5,199,436, 5,645,350, 5,368,038, 5,293,877 and 5,179,936).
A radiant type thermometer has a main body and a probe extending outward from the main body that is inserted in the ear hole (the external auditory meatus) when the temperature of the eardrum is measured. An infrared ray sensor for detecting infrared rays having entered inside the probe from the eardrum when the probe is inserted in the external auditory meatus and a microcomputer for calculating the temperature of the eardrum based on the detection results of the infrared ray sensor are mounted inside the main body. The temperature of the eardrum calculated by the microcomputer is displayed on a display device provided in the main body.
When a user measures the temperature of the eardrum, the user holds the main body and presses a measurement-starting switch after inserting the probe in the external auditory meatus of a subject. Then, the infrared ray sensor detects infrared rays from the eardrum and the microcomputer causes the display device to display the temperature of the eardrum based on the detected infrared rays. The user can recognize the body temperature of the subject by referring to the temperature of the eardrum displayed on the display device.
FIG. 9 illustrates an internal structure of the probe in a conventional radiant type thermometer. A probe 51 is formed in a tubular shape and its inside forms a path connecting its outside and the inside of a main body 55. A waveguide 54 for infrared rays is disposed coaxially with the probe 51 in the path and an infrared ray sensor 52 is disposed on the central axis of the probe 51 inside the main body 55.
In addition, a protecting plate 53a using silicon (Si) or Germanium (Ge) blocks an opening of the head of the probe 51 against infrared rays to prevent foreign material from entering inside the probe 51. Alternatively, as shown in FIG. 10, the end part of the probe 51 of the waveguide 54 is covered by a protecting film 53b using a transparent film made of polyethylene (PE) or polypropylene (PP) with respect to infrared rays to prevent foreign material from entering inside the waveguide 54.
Technologies described below are known as structures using similar protecting members.
For example, Japanese Patent Application Laid-open No. Hei 5-261070 discloses a structure for forming a window made of a glass-like material and the like that is transparent with respect to infrared rays as zinc selenide at the end in a probe side of a waveguide of a radiant type thermometer and preventing a pollutant from entering the waveguide by protecting its circumference with a tubular sleeve. In addition, Japanese Patent Application Laid-open No. Hei 8-189863 discloses a structure of a radiant type thermometer that has a plate-like portion covering the front face of a lens guiding infrared rays from a waveguide of a probe to an infrared ray sensor and a tubular attaching portion, and is detachably equipped with a lens cover made of polyethylene and the like, thereby does not require a probe cover. Moreover, Japanese Patent Application Laid-open No. Hei 8-313357 discloses a structure of a radiant type thermometer that adheres a substantially disc-shaped cover made of an infrared ray transmitting material such as silicon to the end of a probe to prevent foreign matter from entering inside the probe. Furthermore, Japanese Patent Application Laid-open No. Hei 10-118035 discloses a structure of a radiant type thermometer that equips the end of a probe of the thermometer with a shielding member made of an infrared ray transmitting material such as polyethylene and the like and makes the shielding member at the end part of the probe a shielding film having a plurality of small holes to protect the probe. Further, Japanese Patent Application Laid-open No. 11-32998 discloses a structure of a probe of a radiant type thermometer that is covered by a protection sheet made of an infrared ray transmitting resin material so as to cover an end opening of a waveguide to prevent foreign material and the like from entering inside the waveguide.
Foreign material and dusts stick to the above-mentioned protecting plate 53a and protecting film 53b or other protecting members through the use of a radiant type thermometer. Since these foreign material and dusts interrupt infrared rays that should reach the infrared ray sensor 52, these must be removed.
However, the protecting plate 53a and the protecting film 53b as well as other protecting members are only stretched or stuck on the end part of the probe 51 in the direction perpendicular to the central axis of the probe 51. For this reason, it is possible that the protecting plate 53a or the protecting film 53b and the like are damaged by force applied from outside against the protecting plate 53a or the protecting film 53b and the like when foreign material and the like are removed.
In addition, since the protecting plate 53a has higher strength than the protecting film 53b, it is considered that the possibility of damage is lower when the protecting plate 53a is used than when the protecting film 53b is used. However, since the protecting plate 53a is more expensive than the protecting film 53b, there is a problem that manufacturing costs of a radiant type thermometer are higher when the protective plate 53a is used.
An object of the present invention is to provide a radiant type thermometer capable of improving the strength of protecting members such as a protecting plate and a protecting film.
In order to solve the above-mentioned problems, the present invention adopts the following structure:
A first aspect of the present invention is a radiant type thermometer for measuring the temperature of a subject based on infrared rays emitted from the subject wherein the radiant type thermometer is provided with a main body, a tubular probe fixed to the main body with its end protruding from the main body and its inside forming a path of infrared rays from the subject to inside of the main body, a protecting member for blocking an opening in the end side of the probe and transmitting infrared rays and a supporting body disposed in parallel with the central axis of the probe in the path inside the probe with its end part disposed in the direction perpendicular to the central axis being fixed on the internal wall of the probe and supporting the protecting member by contacting the protecting member.
In accordance with the first aspect of the present invention, since the supporting body for supporting the protecting member is provided, the strength of the protecting member can be improved.
The supporting body is provided such that it does not completely block the path. The supporting body can be composed, for example, of a plate-like member. The supporting body can be also composed, for example, of a plurality of plate-like members disposed in parallel to each other. The supporting body can be also composed, for example, of two plate-like members perpendicular to each other. The supporting member can be also composed, for example, of a plurality of plate-like members crossing with each other.
In addition, the supporting body can be composed, for example, of a plurality of plate-like members disposed so that an end face in the direction of the central axis of the probe forms a polygon. If the supporting body is composed of a single or a plurality of plate-like members, the thickness of the plate-like members is preferably an integer times of the wavelength of infrared rays passing through the protecting member. Further, the plate-like member is formed, for example, of polyethylene or polypropylene. The thickness of the plate-like member can be composed of 0.01 mm to 0.5 mm, preferably 0.1 mm to 0.5 mm.
Moreover, the end face in the direction of the central axis of the probe of the supporting body can be composed in the lattice shape.
A second aspect of the present invention is a radiant type thermometer for measuring the temperature of a subject based on infrared rays emitted from the subject wherein the radiant type thermometer is provided with a main body, a tubular probe fixed to the main body with its end protruding from the main body and its inside forming a path of infrared rays from the subject to inside of the main body, a protecting member for blocking an end part of the probe and transmitting infrared rays, and a supporting body disposed coaxially with the central axis of the probe inside the probe with a plurality of through holes having axes parallel with the central axis of the probe and supporting the protecting member by contacting the protecting member.
If the probe and the supporting body are cut in the direction perpendicular to the central axis of the probe, the first and the second aspects of the present invention preferably have the occupancy of the area of the supporting body to the area of inside the probe in the cross section of more than 0% and 50% or less.
In addition, in the first and the second aspects of the present invention, the supporting body can take, for example, a structure in which it is integrally formed with the protecting member. Further, the supporting body can take, for example, a structure in which it is integrally formed with the probe. Alternatively, the supporting body can take, for example, a structure in which the protecting member and the probe are integrally formed.